What does "back box" mean, and what diseases does it check for?

Wearing a Holter monitor refers to carrying a portable cardiac monitoring device for 24-hour continuous heart surveillance, also known as a 24-hour ambulatory electrocardiogram (ECG). It helps detect whether the heart exhibits functional abnormalities. Detailed information is as follows:

A 24-hour ambulatory ECG effectively monitors and records the patient's entire cardiac electrical activity continuously over approximately 24 hours—or even longer—during normal daily activities. The recorded data are then analyzed by computer, enabling accurate identification of arrhythmias, myocardial ischemia, and other conditions that may be missed during routine ECG examinations. This provides crucial objective evidence for clinical diagnosis, treatment decisions, and evaluation of therapeutic effectiveness. Additionally, it helps determine the causes of episodic syncope, dizziness, and palpitations. Furthermore, based on the test results, it allows assessment of a cardiac patient’s prognosis, daily living capacity, and the efficacy of anti-arrhythmic medications and treatments for myocardial ischemia.

When undergoing a 24-hour ambulatory ECG, patients should avoid imaging examinations such as X-rays and magnetic resonance imaging (MRI), as these may interfere with the accuracy of the ECG monitoring.